High-voltage mercury-arc rectifier



Filed Aug. 5, 1965 Dec. 10, 1968 F, BUTAEV ETAL 3,416,018

HIGH-VOLTAGE MERCURY-ARC RECTIFIER 2 Sheets-Sheet 1 /NSUL/ITORS M/ sanrrdRS Dec. 10, 1968 F. BUTAEV ETAL l 3,416,018

HIGHVOLTAGE MERCURY-ARC RECTIFIER Filed Aug. 3, 1965 2 Sheets-Sheet 2United States Patent O 3,416,018 HIGH-VOLTAGE MERCURY-ARC RECTIFIERFilipp Ivanovich Butaev, Krasnokazarmennaya ulitsa '19,

kv. 43; Nikolai Semenovich Klimov, Krasnokazarmennaya ulitsa 19, kv. 94;Alexei Alexandrovich Pertsev, Krasnokazarmennaya ulitsa 19, kv. 136;Nikolai Pavlovich Stepanov, Sadovo-Sukharevskaya ultsa 2/34, kv. 6;Alexandr Mikhailovich Shemaev, Metrostroevskaya ulitsa 9, kv. 3; andIlya Dmitrievich Shkolin, B. Spasskaya ulitsa 7, kv. 15, all of Moscow,U.S.S.R.

Filed Aug. 3, 1965, Ser. No. 476,823 6 Claims. (Cl. 313-30) ABSTRACT OFTHE DISCLOSURE A high-voltage mercury-arc rectifier having intermediateelectrodes, located at the lower end of the anode chamber between theanode and cathode, and formed as a plurality of spaced truncated conesinterfastened by a refractory metal bar. The intermediate electrodes areconnected to a voltage divider by terminals which are constructed ashollow bodies containing hollow bolts with slidable rods therein actedon by springs and carrying contact ferrules on one end thereof.

The present invention relates to high-voltage mercuryarc rectifiers,more particularly, to the design of the anode system `of a high-powerhigh-voltage mercury-arc rectifier.

There are known high-voltage mercury-arc rectifiers comprising a housingwith channels for coolant, an anode chamber, a main anode insulator, ananode, a cathode, intermediate electrodes, a cooler, grids, a filter,excitation anodes, a voltage divider and an evacuation system.

Said high-voltage mercury-arc rectifiers provide power not higher than3.3 mw. per anode.

It has been proposed before to increase the power by usingparallel-connected anodes, but this results in the heavy and bulkydesign of a rectifier.

The main object of the invention is to provide a high-voltagemercury-arc rectifier which permits an increase of power, and minimizessuch phenomena as arcing back and anode and intermediate electrodespu-ttering while reducing the ytemperature of the Imain anode insulatorand electrodes.

In accordance with the invention intermediate electrodes are made ofmonolith truncated cones interfastened by refractory-metal bars havingmetal shield envelopes and are located in the lower part of the anodechamber. To connect intermediate electrodes with a voltage divider,provision is made for sectional terminals constructed as hollow boltswith a rod and a spring inside, said rod having a contact ferrule at itsend, whereas to avoid -misfire of the main discharge, `the voltagedivider is made of low-resistance material. Base insulators which areused to connect cylinders with intermediate electrodes are reinforcedwith metal caps which are applied by cold compression.

Apart from this, to simplify the design, the main anode insulator is ofconical shape.

An embodiment of the invention is given by way of illustration andrepresented in the accompanying drawings, wherein:

FIG. 1 schematically shows a general sectional view of the high-voltagemercury-arc rectifier;

FIG. 2 is a sectional view of the intermediate electrodes;

FIG. 3 is a 4sectional view of a terminal adapted to connect a voltage-divider with the intermediate electrodes;

3,416,018 Patented Dec. l0, 1968 FIG. 4 shows the base insulator FIG. 5shows the main broken away;

FIG. 6 shows the anode cooler.

The high-voltage mercury-arc rectifier comprises the following mainunits; housing 1 (FIG. 1), anode chamber 2, main anode insulator 3,anode 4, cathode 5, anode cooler l6, intermediate electrodes 7, grids 8,filter 9 with cone 10, excitation anodes 11, voltage divider 12 andevacuation system 13 equipped with high-vacuum cock 14.

Referring to FIG. 1, anode chamber 2 is fixed on the upper flange ofhousing 1 and provided with cooling ribs 15. Main anode insulator 3, inits turn, is mounted on the upper plate of anode chamber 2. 'Iierminals16 of excitation anodes 11 as Well as other terminals of auxiliaryelectrodes (not shown in FIG. l) extend through the lower plate of anodechamber 2. To maintain a vapordynamic mode for the rectifier, there areformed in housing 1 channels 17 for the circulation of coolant. Acathode cap 18 is provided with double walls between which coolantcirculates for the same purpose. To maintain the temperature conditionsof anode insulator 3 within the required limits and at high load,intermediate electrodes are extended into the lower part of anodechamber 2, for which purpose cylinders 19 having electrodes 7 in theirlower parts are correspondingly elongated. The intermediate electrodesare formed by a plurality of spaced truncated cones 20 (FIG. 2) whosespacing increases the greater the distance from the axis of therectifier, thereby providing for a uniform current density throughoutthe entire surface of the end part of anode 4. To increase themechanical strength of electrodes 7, cones 20 are assembled on bars 21made of refractory metal, for instance molybdenum. The external surfacesof bars 21 are protected against molybdenum sputtering by iron castings22. Voltage divider 12 (FIG. l) is connected with cylinders 19 ofintermediate electrodes 7 by sectional terminals 23. Each of thetermin-als 23 comprises a hollow bolt 24 (FIG. 3) with shoulof the anodeunit; anode insulator partially insulator 3; contact rod 26 with ferrule27 at its end; and spring 28. Bolt 24 -is pressedagainst insulator 3through metal packing 29 with the aid of nut 30 and spring 31. The endof the hole in bolt 24 is closed by plug 32 and sealed by a vacuum-tightweld. Ferrule 27 is pressed against anode cylinder 19 with spring 28.From the outside, terminal 23 receives active voltage divider 12 (FIG.l) serving to remove negative charges from intermediate electrodes 7 andto sharply reduce the probability of misre of the main discharge.Voltage divider 12 is made of low-resistance material, i.e. materialwith a resistance value at which the time constant of a circuitcomprising the above-mentioned divider and the capacitance between anodecylinders 19 is not more than a frequency cycle of the mains. Baseinsulators 33 with cylinders 19 fixed on them are reinforced with metalcaps 34 (FIG. 4). Caps 34 are fixed to insulators 33 by coldcompression, which considerably simplifies and cheapens themanufacturing process, as compared to the convention-al practice ofexpensive silver soldering of the caps in a vacuum.

The surface of conventional anode insulators of highvoltage mercury-arcrectifiers is of a step-like shape which causes technologicaldifficulties in surface polishing. To simplify a technologicalprocessing and assembling of the rectifier, the internal surface of mainanode insulator 3 is made conic in shape (FIG. 5). This shape of theanode insulator provides for the necessary intervals between theabove-mentioned insulator and the elements of the anode unit.

ders 25, said bolt being passed through a hole in anode The anode cooleris of the conventional design of a system of pipes.

The cooler 6 (FIGS. 1, 6) is made as a closed hollow body with radiator35 in its upper part. When cooler 6 operates, mercury starts boiling atits bottom 36 and the vapors produced in the body go up and condense inradiator 35.

The above-described design of the anode system of a high-voltagemercury-arc rectifier permits to increase the load up to 7.5 mw.

What is claimed is:

1. A high-voltage mercury-arc rectiiier comprising a housing havingchannels for the passage of a coolant; a cooled cathode cap locatedinside said housing; an anode chamber mounted on said housing; a mainanode insulator fixed on said anode chamber; a cathode located in thebottom of said housing; a hollow anode located inside said anode chamberand main anode insulator; an anode cooler located inside said anode;cylinders located inside said anode insulator and anode chamber;intermediate electrodes assembled of truncated cones interfastened withrefractory-metal bars with metal shield envelopes, said intermediateelectrodes being fixed into said cylinders and located in the lower partof said anode chamber between the cathode cap and anode; a filterlocated inside said housing between the cathode cap and intermediateelectrodes; grids located between said intermediate electrodes andfilter; excitation anodes located in said housing; a voltage divider andterminals connecting said voltage divider with said cylinders, saidterminals being passed through holes provided in said anode insulator;and an evacuation system mounted on said housing.

2. A rectifier as claimed in claim 1 wherein each of said terminalscomprises a hollow body, a rod in said body including a contact ferruleon one end thereof and a spring acting on the rod.

3. A rectilier as claimed in claim 1 comprising a capacitor connectedbetween the divider and each cylinder, said voltage divider having aresistance value such that the time constant of a circuit comprisingsaid divider and the capacitance between said cylinders is not more thana frequency cycle of the mains.

4. A rectifier as claimed in claim 1 comprising base insulators for thesupport of said anode cylinders, said base insulators includingreinforcing metal caps which are cold pressed on said insulators.

5. A rectifier as claimed in claim 1 wherein said main anode insulatoris of conical shape.

6. A rectifier as claimed in claim 1 wherein said anode cooler is aclosed hollow body partially filled with mercury.

References Cited UNITED STATES PATENTS 2,301,980 11/1942 Steenbeek313-195 X 2,500,153 3/1950 Cork et al 313-195 X 2,797,348 6/1957 Watrous313-195 X JAMES W. LAWRENCE, Primary Examiner.

R. JUDD, Assistant Examiner.

U.S. Cl. X.R.

